For months, the Bush administration seemed set on making a formal decision that no drinking-water standard for perchlorate was necessary.

Now it appears the Obama administration will get the final say.

In a surprising reversal, the Environmental Protection Agency announced Thursday that it does not plan to decide what the drinking-water standard should be for perchlorate, a common California contaminant used to produce explosives.

The EPA said it would seek the counsel of the National Academy of Sciences, for a second time.

The EPA received more than 32,000 public comments on its preliminary proposal in October not to set a standard.

“They don’t have the backbone to actually go ahead and live up to their responsibility and stand up for public health,” said Renee Sharp, California director of Environmental Working Group,an environmental and public-health advocacy organization.

Perchlorate has been found at 400 sites across the country and in more than 100 sites in California. High levels have been found in Redlands, Rialto and the San Gabriel Valley. Lower levels were found throughout the Inland Empire because it is a type of fertilizer.

Perchlorate can affect thyroid hormone levels, which scientists fear could lead to mental and physical problems in children.

California has a state standard for perchlorate of 6 parts per billion (ppb) in drinking water, though the state has begun reviewing the standard. Massachusetts, which set a standard around the same time as California, has a limit of 2 ppb.

In 2002, EPA scientists developed a draft protective level of 1 ppb, assuming all perchlorate intake comes through water. The Food and Drug Administration has estimated perchlorate from vegetables and dairy foods account for up to 59 percent of perchlorate intake.

A controversy over the proposal of 1 ppb caused the issue to be referred to a National Academy of Sciences committee.

In 2005, the committee developed a recommended reference dose of about 20 ppb, assuming a body weight of 150 pounds and that all perchlorate is ingested through water. That process was criticized as being influenced by the defense industry.

After the EPA announced its intent not to set a standard, which would apply to drinking water nationwide, lawyers at the nonprofit environmental law firm Earthjustice announced they would sue under the Safe Drinking Water Act once the rule was final.

” I think the (EPA) has recognized that it needs to take a closer look at the science regarding perchlorate contamination,” said Earthjustice lawyer George Torgun.

Sharp, of the environmental-advocacy group, said she isn’t sure how the process will move forward under Obama.

Sen. Barbara Boxer, D-Calif., criticized the agency for not setting a standard.

“EPA’s decision to delay setting a drinking water standard for perchlorate is immoral,” Boxer said Thursday. Boxer chairs the Senate’s Environment and Public Works Committee. “This is one of many midnight decisions by the Bush administration that I will raise … next week.”

Join the Conversation

We invite you to use our commenting platform to engage in insightful conversations about issues in our community. Although we do not pre-screen comments, we reserve the right at all times to remove any information or materials that are unlawful, threatening, abusive, libelous, defamatory, obscene, vulgar, pornographic, profane, indecent or otherwise objectionable to us, and to disclose any information necessary to satisfy the law, regulation, or government request. We might permanently block any user who abuses these conditions.

If you see comments that you find offensive, please use the “Flag as Inappropriate” feature by hovering over the right side of the post, and pulling down on the arrow that appears. Or, contact our editors by emailing moderator@scng.com.